JP3337657B2 - Ultrasound diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus in which an ultrasonic transducer is mechanically scanned inside an ultrasonic probe.

[0002]

2. Description of the Related Art As an ultrasonic beam scanning method, an electronic scanning method and a mechanical scanning method are known. In the former method, the array transducer is electronically scanned, thereby scanning the ultrasonic beam. In the latter method, usually, a single transducer is mechanically scanned, whereby an ultrasonic beam is scanned. An ultrasonic probe compatible with such a method is also called a mechanical scan type probe.

[0003] As such a probe, a mechanical sector scan probe used in contact with the body surface and a catheter type probe used by inserting it into a body cavity are known. In a mechanical sector scan probe, a single oscillator is swung and scanned in a medium tank. An ultrasonic wave propagating liquid such as physiological saline or oil is injected into the medium tank, thereby ensuring ultrasonic wave propagation. On the other hand, in a catheter probe, a catheter is inserted into, for example, a blood vessel,
Inside the ultrasonic transducer, rotational scanning (radial scanning) is performed.

In a conventional ultrasonic diagnostic apparatus, when performing ultrasonic diagnostics using the above-described mechanical scanning probe, the scanning position and speed of the transducer are controlled by a scanning control unit. The scanning position is detected by a detector such as an encoder, and the voltage and current of a driving signal to the driving motor are controlled in accordance with the detected position and the speed obtained therefrom. Therefore, a slight displacement is compensated by the above servo control. However, if a load fluctuation exceeding a certain level occurs, the servo control cannot cope with the load fluctuation, and finally the motor stops.

[0005]

By the way, internal load fluctuation and external load fluctuation can be cited as factors of load fluctuation. The internal load fluctuation is a fluctuation in load in the probe, for example, a change in viscosity caused by a change in temperature of the medium. Load fluctuations within a certain range due to such a change in viscosity are compensated for by the servo control described above. External fluctuations are fluctuations in load caused by physical contact with a living body. For example, when the catheter bends and the torque of the rotating wire increases.

[0006] It is desirable that mechanical scanning be performed so as to follow the internal load fluctuation as much as possible. However, if such control is performed with respect to external load fluctuation, a problem may occur in safety. There is.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to enable accurate mechanical scanning control according to a factor of a load change.

Another object of the present invention is to make it possible to follow internal load fluctuations as much as possible and to control external load fluctuations with the highest priority on safety.

[0009]

To achieve the above object of the Invention The present invention, have a ultrasonic transducer for transmitting and receiving ultrasonic waves
An ultrasonic probe , a scanning mechanism for mechanically scanning the ultrasonic transducer within the ultrasonic probe, and an ultrasonic transducer
Load fluctuation detection to detect load fluctuation in mechanical scanning of moving element
Output means, type information indicating the type of the ultrasonic probe, and
Control of the scanning mechanism based on the detected load fluctuation
Means for carrying out, the said type information is in contact with the body surface
When showing the mechanical sector ultrasonic probe used
Selects the load fluctuation tracking priority mode, and
In accordance with the priority mode, the compensation control for making the machine scan follow the load change is executed preferentially, and the type information is
When showing a catheter-type ultrasonic probe inserted into a body cavity
Select the safety priority mode and follow the safety priority mode
The safety control for stopping the mechanical scanning with respect to the load variation
Viewed contains a control unit, the executing priority, wherein, prior to
In the load change tracking priority mode, the load change is the upper limit.
In addition to exceeding the threshold,
Stop the mechanical scanning and enter the safety priority mode
Other than when the load fluctuation exceeds the upper limit,
The apparatus is characterized in that the mechanical scanning is stopped even when the value falls below a limit value . Preferably, in the safety priority mode,
The load fluctuation is between the lower limit value and a predetermined value.
In some cases, follow-up control is performed, and
When the value is between a predetermined value and the upper limit value, the scanning device
The servo gain for the frame is fixed and no alarm is displayed.
Is done.

According to the above configuration, the mechanical sector supersonic is generated.
In the wave probe, stable scanning can be secured by following mechanical scanning with respect to internal load fluctuations such as a change in viscosity of the coupling material. Catheter-like ultrasound probe inserted into body cavity
With respect to the stylus, mechanical scanning can be stopped against external load fluctuation such as pressing by the living tissue to enhance safety.

[0011]

Preferably, the apparatus further includes a load fluctuation detecting means for detecting a load fluctuation based on at least one of a voltage and a current of a drive signal supplied to the motor. Preferably, the apparatus further includes a load fluctuation detecting unit that detects a load fluctuation based on at least one of a scanning position and a scanning speed measured for the ultrasonic transducer.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a main configuration of a preferred embodiment of an ultrasonic diagnostic apparatus according to the present invention.

The probe 10 is an ultrasonic probe inserted into a body cavity or an ultrasonic probe used in contact with a body surface. The vibrator 12 transmits and receives ultrasonic waves, and the vibrator 12 is driven to rotate or swing by a motor 14. The rotation angle is detected by the encoder 16 as the current position. For example, in the case of an ultrasonic probe inserted into a body cavity, a torque wire is inserted into a catheter-like tube, and a vibrator 12 is attached to a distal end portion of the torque wire. Then, the torque wire is rotationally driven by the motor 14 provided on the proximal end side of the catheter tube, whereby the vibrator 12 is rotationally scanned. In the case of a probe used in contact with the body surface, the vibrator 12 is reciprocated by a mechanical scanning mechanism including a motor 14 in the balloon.

The speed signal output from the control unit of the apparatus main body is input to the drive signal generator 18. The drive signal generator 18 generates a drive signal based on the speed signal. In this case, the drive signal corresponds to, for example, a signal obtained by integrating the speed signal. The comparator 20 calculates a difference between the current position output from the encoder 16 and the target position represented by the speed signal, and outputs the difference result to the driver 22. The driver 22 supplies a driver signal to the motor 14 based on the result of the difference based on the set gain G. Here, if there is a difference between the target position and the current position, the driver 22 cancels the difference.
Is controlled, whereby the following drive according to the load fluctuation is performed.

The speed signal is input to the speed comparator 24, and the current position output from the encoder 16 is also input to the speed comparator 24. The current speed is calculated by differentiating the current position, and the difference between the current speed and the target speed represented by the speed signal is calculated.
The difference result is input to the load change controller 26. The difference represents a variation of the actual load from the reference load.

On the other hand, the voltage or current of the driver signal output from the driver 22 is monitored by the voltage / current detector 28, and the detection result is output to the load fluctuation controller 26. The voltage value or the current value is also used as representing the load variation.

The load variation controller 26 includes a difference result output from the speed comparator 24 and a voltage / current detector 28.
Is a circuit that calculates a load variation based on a voltage value or a current value output from the controller 22 and sets a servo gain G or a control condition of the driver 22 according to the load variation. In this case, information on the type of the probe has been input, and the load variation controller 26 determines a control mode based on the information, and executes control according to the determined control mode. The load change controller 26 outputs an alarm message to the outside when a predetermined condition is satisfied.

FIG. 2 shows two control modes of the load change controller 26. (A) shows the follow-up priority mode, and (B) shows the safety priority mode. For example, when the load change is caused by the change in the internal load, the following priority mode shown in (A) is selected, and when the load change is caused by the external load change. , The safety priority mode shown in (B) is selected. Thus, for example, in a mechanical sector probe abutting on the body surface, when a load change occurs due to, for example, a viscosity change of a coupling medium or the like, control that maximally follows the load change is executed according to a follow-up priority mode. Will be done. On the other hand, for example, in the case of an ultrasonic probe inserted into a body cavity, in a case where external load fluctuation is increased due to bending of a catheter tube or pressing by tissue, tracking control is performed only within a certain range according to a safety priority mode. Control is performed to stop driving of the vibrator for a load change equal to or more than a predetermined value.

Specifically, as shown in FIG. 2A, in the following priority mode, the following control is performed when the ratio of the load change is within the range of A on the negative side to B on the positive side. It is executed, and when the value falls below or exceeds the limit value, the mechanical scanning of the probe is stopped. In this case, the reason why the stop control is performed even when the load fluctuation becomes small is that some trouble may occur in the mechanism of the probe. This is the same in the safety priority mode shown in FIG. In this tracking priority mode, the servo gain G is set to sufficiently follow the increase in the load fluctuation, and the
Sufficient driving power is supplied to the motor 14 from the motor 2. As a result, a large load torque can be countered.

On the other hand, in the safety priority mode shown in (B), the follow-up control is executed while the load fluctuation is narrow from C on the negative side to D on the positive side, and the follow-up control is performed from D to E on the positive side. Within the range, a predetermined alarm is displayed on an external display while the gain of the driver 22 is fixed. In this case, for example, a message such as "Stop scanning for load fluctuation and confirm safety around the probe" is displayed. When the load fluctuation exceeds the limit value E, the scanning of the vibrator is forcibly stopped. Therefore, in the safety priority mode, the servo gain is not set excessively even when the load fluctuation increases, and as a result, there is an advantage that safety can always be ensured. That is, even if a load is generated due to the pressing of the living tissue, the vibrator can be stopped without forcibly resisting the load and continuing the rotation drive of the vibrator.

In the embodiment shown in FIG.
Load fluctuation was detected based on the difference in speed or the voltage or current value of the driver signal, but is not limited to this.
Of course, various methods can be applied as long as the load fluctuation can be detected. In the above embodiment, the control mode is selected based on the type of the probe, but the mode may be switched based on other information.
In any case, by realizing the servo control corresponding to the internal load fluctuation and the external load fluctuation, it is possible to improve the reliability of the apparatus while improving the safety.

[0024]

As described above, according to the present invention,
It is possible to realize accurate scanning control according to the factor of the load fluctuation.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main configuration of an ultrasonic diagnostic apparatus according to the present invention.

FIG. 2 is a diagram showing a control mode by a load variation controller.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 probe, 12 transducer, 14 motor, 16 encoder, 18 drive signal generator, 20 comparator, 22
Driver, 24 speed comparator, 26 load change controller, 28 voltage / current detector.

Claims (4)

(57) [Claims] 1. A chromatic ultrasonic transducer for transmitting and receiving ultrasonic waves
An ultrasonic probe , a scanning mechanism that mechanically scans the ultrasonic transducer in the ultrasonic probe, and detects a load change in the mechanical scanning of the ultrasonic transducer.
Load fluctuation detecting means, type information indicating the type of the ultrasonic probe and the detected
Means for controlling the scanning mechanism based on the load fluctuation
Wherein the type information is used in contact with a body surface
Load fluctuation when showing a mechanical sector ultrasound probe
Select the tracking priority mode, and select the load fluctuation tracking priority mode.
Priority is given to the compensation control for making the mechanical scanning follow the load fluctuation in accordance with
Safety-priority mode when showing an ultrasound probe
Select over de, said the safety priority mode controller for real <br/> rows preferentially safety control to stop the mechanical scanning with respect to the load variation in accordance with, seen including, said control unit, the load Before in the variable tracking priority mode
When the load fluctuation exceeds the upper limit,
Stop the mechanical scanning even if it falls below, and
In safety priority mode, the load fluctuation exceeds the upper limit
In addition to the case where the
An ultrasonic diagnostic apparatus, which stops the examination. 2. The apparatus according to claim 1, wherein in the safety priority mode, the load change is lower than the lower limit.
When the value is between the limit value and the predetermined value, the tracking control is executed.
The load fluctuation is between the predetermined value and the upper limit value.
In some cases, the servo gain for the scanning mechanism is fixed
An ultrasonic diagnostic apparatus characterized in that an alarm is displayed by being performed . 3. A device according to claim 1, wherein the load change detection means, Turkey detecting the load change on the basis of at least one of the voltage and current of the drive signal supplied to the motor, wherein the scanning mechanism comprises a An ultrasonic diagnostic apparatus characterized by the above-mentioned. 4. A device according to claim 1, wherein the load change detection means, wherein the benzalkonium detecting the load change based on at least one of said ultrasonic actually measured for transducers scan position and scan speed Ultrasound diagnostic device.